The present invention relates to a miniature electric motor, more especially a miniature synchronous motor, having two identically shaped stator halves which are connected by means of lugs axially interengaging on the circumference of the stator.
In a known miniature synchronous motor of this kind (British Patent Specification No. 1,460,189, FIGS. 1 and 2) a narrow lug of one stator part engages between the pairs of lugs located symmetrically thereto of the other stator part. The laterial contact between the interengaging lugs is limited to a fraction, at the most to about half the axial length of the stator. Thus, for the magnetic flux there is only a narrow lug available on one side. Between two adjoining lugs of adjacent pairs of lugs the laterial edges of the lugs at the most are in mutal line contact, so that at this point substantially no flux can pass through. The magnetic circuit between the two stator parts is therefore relatively bad. Moreover, since the mutual connection of the stator parts occurs exclusively by edge pressure between stamped and bent metal parts, relatively narrow tolerance limits are required during manufacture.
In a further known motor of the above kind, (British Patent Specification No. 1,429,224) the lugs abut with their end faces against the opposite stator part, and only narrow anchoring extensions of the lugs engage in grooves of the stator parts. In this case also the magnetic circuit is not optimal and greatly depends upon the manufacturing accuracy.